The report may be welcome news to those concerned about the nation's obesity epidemic, but the restaurant industry might not relish the findings. Many of the improvements in the American diet are a result of driving past the drive-thru: "Reduced consumption of food away from home (such as food from restaurants and fast food) accounted for 20 percent of the improvements in diet quality," the report found.

The report added: "Calories consumed through food away from home dropped by 127 calories per day, and the average person ate three fewer meals and 1.5 fewer snacks per month away from home," suggesting that every bit helps.

The report also suggests that Americans like nutritional information on restaurant menus, with 76% of working-age adults reported that they would use the information when available.

Perhaps more significantly, the survey of nearly 10,000 people suggests a changing attitude toward food and nutrition with respondents feeling more empowered about their ability to do something about an expanding waistline.

That could be a powerful tool in the fight against obesity.

"When individuals believe that their actions directly affect their body weight, they might be more inclined to make healthier food choices," said study author Jessica Todd of the USDA's Economic Research Service.

The USDA's press statement credited several federal initiatives for the brightening outlook, including MyPlate and its meal planning advice and shopping strategies, SuperTracker (an online food tracking tool), setting healthier guidelines for food and beverages sold in schools, and a 67% increase in the number of farmers markets around the country.

"We have made significant progress, but our work is not done," Agriculture Secretary Tom Vilsack said in the statement. "We will continue to invest in critical programs that expand the availability of healthy, safe, affordable food for all Americans."